Our underlying hypothesis is that there are still many more gradient methods to be developed that can not only improve the capabilities of the state-of-the-art technology, but also provide completely new approaches to study molecular structure and dynamics and to optimize the efficiency of the NMR experiment. These new experiments exploit the specific capabilities of gradients to select signals based on their spatial and motional (e.g. flow, diffusion) characteristics. Our specific aims are: Aim 1) to design gradient analogues for presently-existing NMR pulse sequences that can improve sensitivity and reduce artifacts, especially in the study of exchanging protons. Aim 2) to explore the use of pulsed-field-gradient diffusion-weighted NMR experiments for the study of proton and molecular exchange dynamics. Aim 3) to explore the use of imaging methods for high resolution NMR. Aim 4) to design selective gradient methods for the detection of so- called multiple spin echoes (MSEs) or multiple-quantum spin echoes (MQEs), which occure when a small magnetic field gradient is present over a sample that has a large magnetization component (generally the solvent). Aim 5) to design gradient pulse sequences for studying the metabolic and transport properties of viable cells.